Weighing pan carrier with overload protection device

Abstract

A weighing pan carrier ( 47 ) for a balance with a weighing pan and with a weighing cell that includes a load-receiving portion ( 11 ) and a stationary portion ( 12 ) has an overload protection device against excessive vertically directed forces that is releasably engaged with the weighing pan carrier. The weighing pan carrier ( 47 ) is fastened to the load-receiving portion ( 11 ) of the weighing cell and has on the other hand a fixed connection to the weighing pan. The weighing pan carrier ( 47 ) has a torque safety feature, which is integrated in the overload protection device and provides protection against excessive forces acting tangentially on the weighing pan and/or on the weighing pan carrier ( 47 ) in a direction perpendicular to the direction of the weighing load.

1. A weighing pan carrier ( 47 ) for a balance having a weighing pan for supporting a weighing load and a weighing cell with a load-receiving portion and a stationary portion; the weighing pan carrier ( 47 ) comprising:
 an overload protection device which is fixedly connected to the weighing pan and is normally engaged with the load-receiving portion but is released from engagement therewith under excessive vertically directed forces; and 
 a torque safety feature, integrated in the overload protection device, for protection against excessive horizontally directed forces acting tangentially on the weighing pan. 
 
   
   
     2. The weighing pan carrier ( 47 ) according to  claim 1 , wherein the weighing pan carrier ( 47 ) further comprises a seating cone ( 50 ) for the weighing pan, and the torque safety feature comprises an elastic element that keeps the weighing pan carrier ( 47 ) and the seating cone ( 50 ) in mutual engagement. 
   
   
     3. The weighing pan carrier ( 47 ) according to  claim 2 , wherein the elastic element is a pro-tensioned helix spring ( 51 ). 
   
   
     4. The weighing pan carrier ( 47 ) according to  claim 2 , wherein the torque safety feature comprises mutually engaging elements ( 20 ,  21 ,  31 ,  32 ,  36 ) that serve to uncouple and re-couple the mutual engagement between the seating cone ( 50 ) and the weighing pan carrier ( 47 ). 
   
   
     5. The weighing pan carrier ( 47 ) according to  claim 4 , wherein the mutually engaging elements ( 20 ,  21 ,  31 ,  32 ,  36 ) have at least one detent position for a defined positioning of the weighing pan. 
   
   
     6. The weighing pan carrier ( 47 ) according to  claim 4 , further comprising a restraining stop ( 68 ) which prevents the mutually engaging elements ( 20 ,  21 ,  31 ,  32 ,  36 ) from sliding totally out of engagement when the seating cone ( 50 ) is uncoupled from the weighing pan carrier ( 47 ). 
   
   
     7. The weighing pan carrier ( 47 ) according to  claim 2 , comprising a downward-projecting tubular part ( 52 ) with at least one nose-shaped protrusion ( 20 ) at the lower end of the tubular part, and further comprising a guide bolt ( 53 ) that extends along a line of force introduction, is connected to the seating cone ( 50 ) and has a bolt head ( 15 ) with at least one indentation ( 21 ), wherein the torque safety feature consists of a releasable engagement between the nose-shaped protrusion ( 20 ) and the indentation ( 21 ). 
   
   
     8. The weighing pan carrier ( 47 ) according to  claim 1 , comprising a downward-projecting tubular part ( 152 ) with at least one indentation ( 31 ) at the lower end of the tubular part, and further comprising a guide bolt ( 153 ) that extends along a line of force introduction and is connected to the seating cone ( 50 ), with a transverse pin ( 32 ) installed near a bottom end of the guide bolt, wherein the torque safety feature consists of a releasable engagement between the transverse pin ( 32 ) and the indentation ( 31 ). 
   
   
     9. The weighing pan carrier ( 47 ) according to  claim 2 , comprising a downward-projecting tubular part ( 152 ) with at least one indentation ( 31 ) at the lower end of the tubular part, and further comprising a guide bolt ( 253 ) that extends along a line of force introduction, is connected to the seating cone ( 50 ) and has a bolt head ( 215 ) with at least one upward-directed projection ( 36 ), wherein the torque safety feature consists of a releasable engagement between the projection ( 36 ) and the indentation ( 31 ). 
   
   
     10. The weighing pan carder ( 47 ) according to  claim 5 , wherein the torque safety feature has more than one stable detent position. 
   
   
     11. The weighing pan carder ( 47 ) according to  claim 3 , wherein an amount of force that will release the torque safety feature can be set by adjusting an amount of pre-tension of the helix spring ( 51 ). 
   
   
     12. The weighing pan carder ( 47 ) according to  claim 1 , wherein the weighing cell includes a force-transmitting mechanism that is formed in a material block ( 1 ) as an integral part of the weighing cell. 
   
   
     13. The weighing pan carrier ( 47 ) according to  claim 12 , wherein the force-transmitting mechanism comprises a parallelogram linkage ( 3 ,  6 ,  11 ,  12 ), at least one coupling element ( 16 ), and at least one force-transmitting lever ( 27 ) constituted by material portions of the material block that are separated from each other by material-free spaces. 
   
   
     14. The weighing pan carder ( 47 ) according to  claim 13 , wherein the material block has a main plane and the material-free spaces are configured as narrow linear cuts ( 2 ) traversing the material block ( 1 ) perpendicular to the main plane.